Large Load Development

Both NERC’s State of Reliability Report and Texas RE’s Assessment of Reliability Performance highlight the challenges to grid reliability associated with the rapid growth of large computational loads. On June 18, a significant milestone was reached after extensive work by stakeholders and ERCOT to meet this challenge. The PUCT approved PGRR145, the batch process for large load interconnections over 75 MW. ERCOT and stakeholders hammered out this process to deal with the volume of requests for interconnection by prospective large loads. The traditional process handled each interconnection request serially, and the volume of requests made it inadequate, both for grid planners studying system impacts and for developers facing delays and uncertainty about status of their requests. The transition is underway, with the first “Batch 0” commencing in July to simultaneously evaluate a group of large load interconnection requests that meet PGRR145 criteria. A plan for future batch studies is targeted for September’s ERCOT Board. 

On the national level, FERC’s Commissioner’s unanimously approved orders to the six RTO/ISOs outside our Region to meet its goal to act on last year’s Advanced Notice of Proposed Rulemaking (docket RM-26-4-000) on large loads. Instead of a broad final rulemaking, these “show cause” orders require each ISO/RTO to justify or propose reforms related to their large load interconnections within 60 days. The aim is to streamline processes to enable rapid but reliable interconnection of data centers, while also seeking transparency on cost allocation and co-location with generators.

The industry must also consider concerns about operational performance of data center equipment raised in NERC’s whitepaper on electrical characteristics of large computational loads and risk mitigation guideline. NERC’s Large Load Action Plan focuses on addressing these issues. One element, the Essential Action Alert on Large Computational Loads, provides recommendations and will collect information on existing practices; responses are due August 3. Experts with grid and data center perspectives in NERC’s Large Load Working Group and Load Modelling Working Group continue to meet to develop whitepapers, technical references, and reliability guidelines. Initial stakeholder comments on proposed Computational Load registry criteria in NERC Rules of Procedure and new Reliability Standard requirements under Project 2026-02 are under review, with a second posting for public comments expected in mid-August.

These efforts will complement work in ERCOT to develop ride-through requirements (NOGRR282), dynamic model submission and review requirements (PGRR144), and a proposal for managing large load power variations. Also, ERCOT’s system-wide voltage ride-through assessment for existing large loads seeks to identify areas where MW load loss after a transmission disturbance could exceed 3200 MW and require operational mitigations.